chore(deps): update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/image-build.yml

@@ -17,7 +17,7 @@ jobs:
   lint:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+      - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
       - uses: hadolint/hadolint-action@2332a7b74a6de0dda2e2221d575162eba76ba5e5 # v3.3.0
         with:
           dockerfile: Dockerfile
@@ -55,7 +55,7 @@ jobs:
               imapfilter_spec=${{ needs.grab-imapfilter-latest.outputs.tag }}
 
     steps:
-      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+      - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
       - uses: docker/setup-qemu-action@29109295f81e9208d7d86ff1c6c12d2833863392 # v3
         with:
           # Spurious segfaults when compiling